From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B931C3A59C for ; Fri, 16 Aug 2019 15:58:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5E8BE2171F for ; Fri, 16 Aug 2019 15:58:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="tvPwPtQ4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727397AbfHPP6z (ORCPT ); Fri, 16 Aug 2019 11:58:55 -0400 Received: from pandora.armlinux.org.uk ([78.32.30.218]:59568 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727347AbfHPP6y (ORCPT ); Fri, 16 Aug 2019 11:58:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=elvBvWVjA5zEKSsmKbJEnexDrHQ4zbh3H23MLrNFngo=; b=tvPwPtQ4nFDYaEWEEzQfKWjwT qpues7whqp46I5Vlpf5mw8wLLXsjKZKhYL3qENDObHr6e/tfvEqxnobSqk7I+o8v6P6iqggBm6bK8 +y3guiVg8OfWpHZ8bh58NmAeKwmeX0HupBG5xVopY34VS5LqkUavmbNU6noiQQopZ1a4mq9fGdq6p c5KbXcAx4K1KtIkxoRHLI/wqpZf4RM43n0pGEclxKe0aaadyBCwVAPigha/G0PUIBxsj4OfqNCkkw FxLd0qpy6KdFuAW2HwhGMe+61mqPkgsxj3ISsxS3g1BEReMjus1jWj7xe4EIHYxHqFNmDHQ2jXorL 8vxupwB3g==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:57356) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1hyecj-00034q-B3; Fri, 16 Aug 2019 16:58:41 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1hyecb-00023W-PW; Fri, 16 Aug 2019 16:58:33 +0100 Date: Fri, 16 Aug 2019 16:58:33 +0100 From: Russell King - ARM Linux admin To: Aaro Koskinen Cc: Linus Walleij , Martin Michlmayr , Peter Teichmann , Arnd Bergmann , "open list:GPIO SUBSYSTEM" , Linux Kernel Mailing List , soc@kernel.org, Bartosz Golaszewski , Vinod Koul , linux-i2c , dmaengine@vger.kernel.org, Dan Williams , Linux ARM Subject: Re: [PATCH 1/7] [RFC] ARM: remove Intel iop33x and iop13xx support Message-ID: <20190816155833.GL13294@shell.armlinux.org.uk> References: <20190809162956.488941-1-arnd@arndb.de> <20190809163334.489360-1-arnd@arndb.de> <20190812094456.GI10598@jirafa.cyrius.com> <20190816154249.GA30291@darkstar.musicnaut.iki.fi> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190816154249.GA30291@darkstar.musicnaut.iki.fi> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On Fri, Aug 16, 2019 at 06:42:49PM +0300, Aaro Koskinen wrote: > Hi, > > On Wed, Aug 14, 2019 at 10:36:01AM +0200, Linus Walleij wrote: > > On Mon, Aug 12, 2019 at 11:45 AM Martin Michlmayr wrote: > > > As Arnd points out, Debian used to have support for various iop32x > > > devices. While Debian hasn't supported iop32x in a number of years, > > > these devices are still usable and in use (RMK being a prime example). > > > > I suppose it could be a good idea to add support for iop32x to > > OpenWrt and/or OpenEmbedded, both of which support some > > pretty constrained systems. > > This platform is not really too constrained... E.g. on N2100 you have > 512 MB RAM, SATA disks and gigabit ethernet. Not that different from > mvebu that Debian currently (?) supports. Maybe with multiplatform they > could support iop32x again. Probably not. The kernel has a dividing line between ARMv5 and ARMv6 where it's not possible to multiplatform across that boundary, so you're already needing separate kernel images there. Secondly, armhf distros won't be compatible with ARMv5, and to make them compatible will make performance on armhf suffer - you have to stop using barriers, exclusive load/store and a few other things. You have to rely on the kuser page exported by the kernel (which is now optional as it's deemed to be a security issue for ROP attacks) for some things that such a userspace requires - such as NPTL support. Effectively, ARMv5 is an entirely separate userspace distro from armhf. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up